Question

youre driving down the highway and a bug spatters into your windshield. which undergoes the greater change in momentum during the time of contact? your car the bug both the same question 8 1 pts a karate chop is more effective if ones hand bounces upon impact. extends the time upon impact. follows through upon impact.

Explanation:

Step1: Recall momentum - conservation law

In a closed - system (the car - bug collision is a nearly closed system during the short contact time), the total momentum before the collision equals the total momentum after the collision. According to Newton's third law, the force exerted by the car on the bug is equal in magnitude and opposite in direction to the force exerted by the bug on the car during the contact.

Step2: Analyze change in momentum

The change in momentum of an object is given by $\Delta p = F\Delta t$. Since the forces $F$ on the car and the bug are equal in magnitude and the contact time $\Delta t$ is the same for both, the change in momentum of the car and the bug are equal in magnitude but opposite in direction.

Step3: Analyze karate - chop situation

The impulse - momentum theorem is $J=\Delta p = F\Delta t$. When the hand bounces upon impact in a karate chop, the change in velocity of the hand is larger (it goes from moving towards the target to moving away), which means a larger change in momentum. Since $\Delta p = F\Delta t$, for a given $\Delta t$, a larger $\Delta p$ results in a larger force $F$, making the karate chop more effective.

Answer:

For the first question: C. both the same
For the second question: A. bounces upon impact.